This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1902 edition. Excerpt: ... more so than the corresponding salt of hypoxanthin, and is deposited in glistening six-sided plates, often forming aggregations. Its solution does not precipitate platinum chlorid. The nitrate forms fine yellow crystals which when pure are colorless. The sulphate, Cjhoj.hjso + HjO, crystallizes in ...
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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1902 edition. Excerpt: ... more so than the corresponding salt of hypoxanthin, and is deposited in glistening six-sided plates, often forming aggregations. Its solution does not precipitate platinum chlorid. The nitrate forms fine yellow crystals which when pure are colorless. The sulphate, Cjhoj.hjso + HjO, crystallizes in microscopic, glistening, rhombic plates, decomposable by water. With baryta water xanthin forms the difficultly soluble compound C5HN40, .Ba(OH)J, which corresponds to the hypoxanthin salt C5H4N4O.Ba(OH) and to that of guanin. On the addition of a very small amount of sodium hydrate to xanthin it dissolves, and very soon small white needles separate. The crystals dissolve in excess of alkali. This xanthin-sodium compound, C5H, NaN402 + HjO, is also obtained by passing carbonic acid into an alkaline solution of xanthin. It forms small bunched needles, which are rather easily soluble in water, imparting an alkaline reaction. On the addition of acetic acid the pure white base is thrown down. The compound is partly dissociated by hot water, and resembles the corresponding primary uric acid salts. It is probable that xanthin can form, like uric acid, a soluble secondary salt, since with excess of sodium hydrate it forms a readily soluble compound which probably contains two atoms of sodium. For the reactions of this compound, see page 373. (See heteroxanthin and paraxanthin.) It does not give a mono-methyl xanthin by heating with methyl iodid (Balke). The water of crystallization is expelled only at 190-200. From ammoniacal solution silver nitrate precipitates the colorless compound CjHJOj.AgjO, which is unaltered by short boiling and is insoluble in ammonia, but soluble in hot nitric acid. From the nitric acid solution, on long standing, there..
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